1. Field of Invention
This invention relates to tissue positioning devices to treat sleep disorders.
2. Related Art
Obstructive Sleep Apnea (OSA) is intermittent airflow blockage during sleep caused when the tongue and other soft tissue move backwards and block the airway. Numerous blockages happen during the night, resulting in poor quality sleep and intermittent oxygen deprivation. Approximately 20 million Americans and 35 million people worldwide have obstructive sleep apnea and the number is growing rapidly.
There are many direct and indirect harmful effects of obstructive sleep apnea. Potential harmful effects include: disrupted sleep; chronic fatigue; morning headaches; irritability; brain damage; cognitive dysfunction; impotency; high blood pressure; heart attacks; congestive heart failure; motor vehicle crashes; job-site accidents; and even death. Despite these harmful effects, it is estimated that only 5% to 8% of the affected population are treated.
Methods in the related art for treating obstructive sleep apnea include: Continuous Positive Airway Pressure (CPAP); surgical removal of soft tissue; surgical advancement of the jaw or tongue; surgical implantation of a tissue anchor; surgical implantation of a tissue stiffening implant; insertion of a tube or stent in the airway; electrical nerve and muscle stimulation; jaw-positioning appliances: non-dynamic tissue-positioning appliances using suction or friction; and other approaches (including magnets, tongue piercing, external body positioning structures, and pharmaceuticals). As we will now discuss, current applications of all of these approaches have significant disadvantages.
1. Continuous Positive Airway Pressure (CPAP):
Continuous Positive Airway Pressure (CPAP) is a means of keeping the airway open by constant positive air pressure. With CPAP, a machine continuously pumps positive pressure air (at a higher pressure than ambient air) into a mask that the sleeper wears on their face. The positive pressure keeps the airway open. CPAP is first-line therapy for the vast majority of people who are diagnosed with obstructive sleep apnea.
However, CPAP has many disadvantages and only a fraction of the people who are prescribed CPAP as therapy continue to use it. Disadvantages of CPAP include: wearing the mask can be very uncomfortable, limit freedom of movement during sleep, and cause a claustrophobic feeling; positive airway pressure can have a negative affect on exhaling and spontaneous respiration; the noise of the machine can disturb the patient or others in the same room; it is difficult to maintain a good seal of the mask to the face; it can dry out nasal passages and cause congestion; it can cause sore eyes, headaches, abdominal bleeding, chest muscle discomfort, nosebleeds and skin rashes; the machine can be expensive; and the machine can be difficult to transport when traveling.
2. Surgical Removal of Tissue:
An invasive approach to treating obstructive sleep apnea is surgical removal of tissue. Surgical treatments to remove tissue include: uvulopalatopharyngoplasty (UPPP)—removal of a portion of the soft tissue of the soft palate and/or pharyngeal walls; glossectomy—removal of a portion of the tissue of the tongue; and glossectomy. There are significant disadvantages with surgical tissue removal. It: is very invasive with relatively high failure rates and associated health risks; is irreversible; often causes significant pain and discomfort; is costly; has a long recuperative period; can cause speech impairment; can cause food and liquids to enter the nasopharynx during swallowing; and can even lead to episodes of choking.
3. Surgical Advancement of the Jaw or Tongue:
Another invasive surgical approach involves surgically moving structures and tissues forward, away from the airway. These surgeries include: mandibular advancement (in which the mandible is cut bilaterally posterior to the last molar and moved forward); maxillomandibular advancement (involving a portion of the jaw bone and teeth plus the portion of the skull to which the teeth are attached); and genioglossal advancement (pulling the genioglossus muscle in an anterior direction to bring the tongue forward). Disadvantages of such advancement surgeries include: its invasiveness; it does not always correct the problem; associated health risks; significant pain and discomfort; high cost; long recuperative period; potential speech impairment; and potential swallowing problems.
4. Surgical Implantation of a Tissue Anchor:
A third surgical approach involves implanting an anchor in soft tissue (such as the tongue), inserting a screw in a fixed structure in the mouth area (such as the base of the mandible), and then attaching them to each other (such as with a suture) to hold the soft tissue in position. Disadvantages of using tissue anchors for obstructive sleep apnea include: although less invasive than surgical removal of tissue, this still involves the costs and risks of surgery; results on effectiveness have been mixed; anchors can migrate in soft tissue and extrude from the tissue; pain and discomfort; speech impairment; and swallowing problems.
Related art involving surgical implantation of a tissue anchor includes U.S. Pat. Nos. 5,988,171 (Sohn et al.), 7,213,599 (Conrad et al.), 7,237,554 (Conrad et al.), 7,337,781 (Vassallo), and U.S. Patent Applications 20060207606 (Roue, Chad et al.), 20060207608 (Hirotsuka, Mark et al.), 20060207612 (Jackson, Jasper et al.), 20070144534 (Mery, Carlos et al.), 20070144539 (van der Burg, Erik et al.), 20070261701 (Sanders, Ira), 20080035160 (Woodson, Beverly et al.), 20080041398 (Hegde, Anant et al.), 20080058584 (Hirotsuka, Mark et al.), and 20080188947 (Sanders, Ira).
5. Surgical Implantation of a Tissue-Stiffening Implant:
Another surgical approach involves implanting a structure that stiffens soft tissue such as the soft palate or tongue. Disadvantages of using tissue-stiffening implants to treat obstructive sleep apnea include: although less invasive than surgical removal of tissue or a tissue anchor, this still involves the costs and risks of surgery; implants can extrude; and effectiveness of this approach for treating sleep apnea is still under investigation.
Related art involving implantation of a tissue stiffening implant includes U.S. Pat. Nos. 6,250,307 (Conrad et al.), 6,401,717 (Conrad et al.), 6,450,169 (Conrad et al.), 6,513,530 (Knudson et al.), 6,513,531 (Knudson et al.), 6,516,806 (Knudson et al.), 6,523,542 (Knudson et al.), 6,523,543 (Conrad et al.), 6,601,584 (Knudson et al.), 6,626,181 (Knudson et al.), 6,634,362 (Conrad et al.), 6,848,447 (Conrad et al.), 7,028,691 (Knudson et al.), 7,036,515 (Conrad et al.), 7,047,979 (Conrad et al.), 7,063,089 (Knudson et al.), 7,100,613 (Conrad et al.), 7,255,109 (Knudson et al.), 7,322,993 (Metzger et al.), and U.S. Patent Applications 20050268922 (Conrad, Timothy et al.), 20050284485 (Nelson, Lionel et al.), and 20070204866 (Conrad, Timothy et al.).
6. Tube or Stent:
In theory, an inserted tube or stent can keep the airway open. However, the airway has a lot of sensory innervation that causes reflex gagging and coughing in response to foreign objects. Related art involving insertion of a tube or stent in the airway includes U.S. Pat. Nos. 5,950,624 (Hart), 6,901,928 (Loubser), 6,976,491 (D'Agosto), 7,363,926 (Pflueger et al.), and U.S. Patent Applications 20040134491 (Pflueger, Russell et al.), 20050199248 (Pflueger, Russell et al.), 20060070626 (Frazier, Andrew et al.), 20060157055 (Pflueger, Russell et al.), 20080035158 (Pflueger, Russell et al.), and 20080223367 (Cox, Brian et al.).
7. Electrical Nerve and Muscle Stimulation:
An investigative approach to treating sleep apnea involves electrical stimulation of nerves or muscles that move soft tissue (such as the tongue) away from the airway. For example, the genioglossus muscle may be stimulated via electrodes on the mucosa on the floor of the mouth. This approach has potential advantages, but is not yet clinically proven and will involve the costs and risks associated with surgery. Related art involving electrical nerve and muscle stimulation includes U.S. Patent Applications 20080103545 (Bolea, Stephen et al.) and 20080161877 (Kirby, Todd et al.).
8. Jaw-Positioning Appliances:
Jaw-positioning oral appliances attach to the teeth. They hold the lower jaw forward to encourage forward movement of the tongue and soft palate. Disadvantages of jaw-positioning oral appliances include: they can cause TemporoMandibular Joint (TMJ) pain; they can be uncomfortable to wear and patient compliance is limited; they can be detrimental to the normal bite relationship of the dental arches; appliances that must be custom fitted are expensive; and forward positioning of the jaw does not always ensure forward positioning of the tongue and soft palate. Related art involving jaw-positioning appliances includes U.S. Patent Application 20080223367 (Cox, Brian et al.).
9. Non-Dynamic Tissue-Positioning Appliances Using Suction or Friction:
There are non-dynamic tissue-positioning appliances, without actively-moving members that hold or move the tongue, in the related art. Such non-dynamic appliances hold the tongue up, down, or forward using suction or friction. Disadvantages of appliances that use suction to hold the tongue include: when a patient swallows or otherwise moves their tongue, the vacuum can be broken and the wandering tongue may never be re-engaged in the device; and continuous suction can cause pain, swelling and edema in tongue tissue. The main disadvantage of non-dynamic appliances that use friction to hold the tongue is that—if they hold the tongue tightly then they are uncomfortable and the constant pressure points can injure tongue tissue, but if they hold the tongue loosely then the tongue can wriggle free during sleep and cause airway blockage.
Related art involving non-dynamic tissue-positioning appliances using suction or friction includes U.S. Pat. Nos. 4,196,724 (Wirt et al.), 4,304,227 (Samelson), 4,676,240 (Gardy), 5,154,184 (Alvarez), 5,373,859 (Formey), 5,649,540 (Alvarez et al.), 5,810,013 (Belfer), 5,915,385 (Hakimi), 5,921,241 (Belfer), 5,957,133 (Hart), 5,988,170 (Thomas), 6,055,986 (Meade), 6,244,865 (Nelson et al.), 6,267,591 (Barstow), 6,295,988 (Sue), 6,408,852 (Tielemans), 6,467,484 (De Voss), 6,494,209 (Kulick), 6,766,802 (Keropian), 6,877,513 (Scarberry et al.), 7,073,506 (Robertson et al.), 7,137,393 (Pivovarov), 7,367,340 (Nelson et al.), 7,451,767 (Keropian), and U.S. Patent Applications 20040045556 (Nelson, Lionel et al.), 20040237965 (Bibi, Noam et al.), 20050150504 (Heeke, David et al.), 20050166929 (Jiang, Yandong), 20060130850 (Chen, Haidong), 20060289013 (Keropian, Bryan), 20070028926 (Kotani, Hiroo), 20070289600 (Li, Kasey), 20080210244 (Keropian, Bryna), and 20080289637 (Wyss, Arthur).
10. Other Approaches:
There are a variety of other efforts to address obstructive sleep apnea, but many are still under investigation and they have not been shown to be effective and acceptable. These other approaches include: using magnetic implants to keep the airway open; piercing the tongue and anchoring the piercing member to an oral appliance; external devices to position the body such as chin straps, head straps and support pillows; and pharmaceutical treatments such as respiratory stimulants and tricyclic antidepressants.
Related art involving other approaches (including magnets, tongue piercing, external body positioning structures, and pharmaceuticals) includes U.S. Pat. Nos. 4,978,323 (Freedman), 5,046,512 (Murchie), 5,176,618 (Freedman), 6,408,851 (Karell), 6,935,335 (Lehrman et al.), 6,955,172 (Nelson et al.), 7,073,505 (Nelson et al.), 7,107,992 (Brooks et al.), 7,188,627 (Nelson et al.), 7,216,648 (Nelson et al.), 7,331,349 (Brady et al.), and U.S. Patent Applications 20040045555 (Nelson, Lionel et al.), 20040045556 (Nelson, Lionel et al.), 20040049102 (Nelson, Lionel et al.), 20060005843 (Nelson, Lionel et al.), 20050133026 (Seleznev, Katie et al.), 20050267321 (Shadduck, John), 20060266369 (Atkinson, Robert et al.), 20060270889 (Nelson, Lionel et al.), 20070089756 (Nelson, Lionel et al.), 20070102004 (Nelson, Lionel et al.), 20070137654 (Paraschac, Joe et al.), 20070137655 (Paraschac, Joe et al.), 20070144532 (Gillis, Edward et al.), 20070144533 (Nelson, Lionel et al.), 20070163603 (Sikora, Val J.), 20070209664 (Paraschac, Joseph et al.), 20070267027 (Nelson, Lionel et al.), 20070270631 (Nelson, Lionel et al.), and 20070272257 (Nelson, Lionel et al.).
To summarize the related art, all of the current approaches to treating obstructive sleep apnea have significant disadvantages. Obstructive sleep apnea remains a widespread condition with serious health consequences with inadequate treatment options. There remains a need for a less-invasive, more-effective, less-burdensome treatment for obstructive sleep apnea with fewer negative side effects.